The 1990s were a time of great economic growth and prosperity. Innovations in technology and decreased defense spending after the Cold War left businesses and governments with significant funding for infrastructure improvements. Investments in transportation, mining and energy production presented an opportunity for the company to grow.
During the decade, Louis Berger began to undertake a wider range of large-scale infrastructure projects. The firm provided consulting services for mass transit and subway projects in the United States, Turkey, Thailand and Hungary, and began its first Superfund project at Fort Riley, Kan. Louis Berger provided engineering and economic services for Yangshan Port in Shanghai, China, and BergerABAM, a Louis Berger affiliate, completed major port projects in the United States and Panama.
- 1991: Louis Berger began a 20-year assignment serving as program manager for the development of a comprehensive combined sewer overflow abatement program in Providence, R.I., in support of the Narragansett Bay Commission.
- 1991: Louis Berger prepared an overall development plan comprising eight separate master plans for the Freeport Mining Company to improve infrastructure in Irian Jaya, Indonesia.
- 1992: Louis Berger prepared the Trans-Hudson crossings master plan for the Port Authority of New York and New Jersey.
- 1994: Louis Berger acquired Ammann & Whitney, a worldwide leader in the rehabilitation and construction of long-span bridges and complex structures.
- 1995: USAID selected Louis Berger to manage the Growth with Equity in Mindanao program to stimulate economic growth and mitigate conflict through infrastructure development, workforce preparation, business development, governance improvement and former combatant reintegration. More than 100,000 Filipinos have escaped poverty supported by the program.
- 1998: Louis Berger began providing project management services for the extension of a 7-kilometer metro line in Budapest, Hungary.